FIX LibVNC url

Dockerfile

@@ -69,7 +69,7 @@ RUN ssh-keyscan gitlab.com >> /root/.ssh/known_hosts
 ## Install latest x11vnc
 RUN mkdir -p /opt
 WORKDIR /opt
-RUN git clone git://github.com/LibVNC/x11vnc
+RUN git clone https://github.com/LibVNC/x11vnc.git
 ### Download source deps
 RUN sed -i.bak -e 's/^# \(deb-src .*\)$/\1/' /etc/apt/sources.list
 RUN apt-get update